E46 series BMW 3

since 1998 of release

Repair and car operation



E46 series BMW 3
+ BMW 3 Cars (Е46)
+ Current leaving and service
+ Engine
+ Systems of cooling, heating
- Power supply systems, injection and release
   Security measures and rules of observance of purity at work with fuel system
   Removal and installation of the sensor of a stock of fuel / fuel pump
   Check of the sensor of a stock of fuel
   + Power supply system of petrol engines
   + System of injection of fuel of the petrol engine
   + Power supply system of diesel engines
   - System of production of the fulfilled gases
      Operation of the catalytic converter
      Security measures for an exception of damages of the catalytic converter
      Turbokompressor
      Removal and installation of system of release
      Check of tightness of system of production of the fulfilled gases
      Removal and installation of the sensor of oxygen
      Removal and installation of a final collector
+ engine Electric equipment
+ RKPP and transmission line
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ electric equipment Schemes



2d97642e


Operation of the catalytic converter

Catalytic converter

1 — the case
2 — consolidation

3 — honeycombs of catalytic converter


All engines are equipped by one or several catalytic converters for purification of exhaust gases.

The catalytic converter has the central ceramic part of a cellular design-3-covered with a layer of the carrier. On a layer of the carrier there are the salts of precious metals operating as converters. The catalytic converter is fixed in the case-1-by means of the insulating basic layer-2-compensating at the same time thermal expansions of the catalytic converter.

To reduce by means of the catalytic converter harmful emissions, systems of injection should dose out precisely amount of the injected fuel necessary for combustion. The sensor of oxygen is in a reception pipe in front of the catalytic converter and is washed by a stream of the fulfilled gases. The sensor of oxygen represents the electronic sensor measuring the content of oxygen in final gases and representing its type of fluctuations of tension. Information from the sensor of oxygen is transferred to the control unit of system of injection. The received value allows to regulate structure of an air-petrol mix. On the one hand it is necessary, as service conditions (the idling, full gas), on the other hand, constantly change as optimum reburning of fuel in the catalytic converter occurs only in this case if final gases contain fuel enough.

That in the catalytic converter there was a fuel reburning, it is necessary to have temperature 300 - 800°С. For this purpose the bigger content of fuel in a mix, than for pure burning is necessary.

Applied catalytic converters of petrol engines represent so-called three-functional devices. In adjustable process of transformation oxidation of an oxide of carbon (WITH) and hydrocarbon (NANOSECOND), and also reduction of concentration of oxides of nitrogen (NOx) is carried out.